The Nighthawk will be available to a select few business customers starting Friday, Dec. 21. The so-called "mobile puck" will be available for free for 90 days, with 5G data usage "at no cost for at least 90 days," AT&T said.

So how does the average Joe -- or Jill -- Schmoe get in on that deal? They don't. According to AT&T, businesses are the "starting point" for this limited 5G launch.

"Initially, we're communicating directly with businesses in the areas where we are bringing mobile 5G to educate them on the power of 5G and invite them into this initial offer," an AT&T spokesperson told Light Reading via email.

The wider public will be able to get the Nighthawk 5G "next spring," for $499 upfront. The contract will include "15GB of data for $70 a month," AT&T says of its upcoming 5G offering.

The $70 pricing is similar to Verizon Communications Inc. (NYSE: VZ)'s Home 5G. The difference being that Verizon's pre-standard service is a fixed wireless offering, as opposed to AT&T's mobile offering. AT&T is, like Verizon, marketing its millimeter wave service under a (slightly) new name -- "5G+."

In the first half of 2019, AT&Ts plan to deploy mobile 5G in parts of these seven additional cities: Las Vegas, Nashville, Orlando, Los Angeles, San Diego, San Francisco and San Jose.

AT&T is offering minimal information on coverage and download speeds so far. "The 5G mobile hotspot operates on mmWave, which is comprised of frequencies with very short-range coverage," an AT&T spokesperson tells us. "As we continue to expand our network we'll deploy more small cell-like infrastructure to help distribute the connection across a particular area."

AT&T says the 5G hotspot is designed to "eventually reach a peak theoretical speed" up to 979 Mbit/s "in ideal lab conditions," AT&T says. While "actual speeds will be lower." The Nighthawk will also support 4G LTE and LTE-Advanced, which AT&T calls "5G Advanced" connections. (See 5G Demos Show the Tech's Spectrum Achilles Heel.)

Mobile 5G in mmWave is a phenomenal achievement With the caveat that I haven't had "hands-on" with the service yet, launching mobile 5G in mmWave in 2018 is a phenomenal achievement.

Yes, it's limited -- because it is early and difficult. The first 3G and 4G launches were similar. 5G will improve on the same sort of trajectory.

Focusing on businesses for the launch makes sense -- 5G arguably represents a swing back to enterprise from consumer and with "friendly" enterprise users you have a controlled group of users. 4G launched in the same way in many countries.

Dan -- you should try and get a trial device in one of these markets for a day or two.